The present invention relates to an automatic exposure control device which can select an automatic exposure control operation of either the aperture dominant type or the shutter speed dominant type.
In the so-called "automatic exposure control operation of shutter speed dominant type" (hereafter referred to as the "EE mode operation") wherein the aperture level of a photographic lens system is controlled in response to the brightness of an object, the sensitivity of film and the exposure time, the operator can easily take into consideration the motion of the object by selecting a high shutter speed for an object which has swift motion. For the depth of field, however, the EE mode operation is constrained to follow the aperture level, which is determined automatically. Thus, the EE mode operation is not fully satisfactory in certain cases, because, for example, the depth of field is the most important picturing element in the case where the object is a still article.
On the other hand, an absolutely contrary conclusion can be deduced for "automatic exposure control operation of the aperture dominant type" (hereafter referred to as "ES mode operation"), wherein the exposure time of a shutter is controlled in response to the brightness of an object, the film sensitivity and the selected aperture level. For example, an excessive exposure time may be imparted to an object of swift motion, because the selection of shutter speed is not left to the photographer.
Since neither of the conventional automatic exposure control operations is always suitable, it would be desirable to have a control device, in which selection can be made between the automatic exposure control operations of the aperture dominant type and of the shutter speed dominant type by simplified changeover means in accordance with the condition of an object.